JPH0588018B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a dedicated transmission line such as a coaxial cable and a power line as an information transmission line in a home automation system, and provides information conversion between them. The present invention relates to transmission systems, and particularly to gateways that convert signals between dedicated transmission lines and power lines.

[Conventional technology]

FIG. 13 is a block diagram showing a household load control system in which a dedicated transmission line and a power line are installed overlappingly, as shown in, for example, Japanese Patent Application Laid-Open No. 60-149242. 2 is a coaxial cable as a dedicated transmission line, and 3 is a power line.
4 is an expanded room A, in which a dedicated line transmission system a is installed using a coaxial cable 2 and a dedicated line transmission system controller 5, and each load 6 such as a doorbell and lighting is controlled by this dedicated line transmission system a. . On the other hand, 7 and 8 are existing rooms B and C, in which each load 10 such as a lighting fixture or a power outlet is controlled by a power line transmission system b equipped with a power line transmission system outlet controller 9 using a power line 3. .

11 is a gateway inserted between the coaxial cable 2 and the power line 3;
are leased line transmission system a and power line transmission system b
By mutually converting control signals between the dedicated line transmission system controller 5 and the dedicated line transmission system controller 5, it is possible to remotely control a load 10 such as a lighting fixture connected to the power line. 12 is a branch part.

FIG. 14 is a block diagram showing the internal configuration of this gateway 11, in which 13 and 14 are signal detection circuits that detect the signals of the coaxial cable 2 and the power line 3, respectively, and 15 and 16 are the signal detection circuits 13 and 1.
Data conversion circuits 17 and 18 convert the signals detected in 4 into power line 3 and coaxial cable 2;
This is a data signal transmission circuit that transmits data to the top. This gateway 11 detects only a data signal by a signal detection circuit 13, converts it into a data signal for power line transmission by a data signal conversion circuit 15, and then sends a data signal to the power line 3 side by a data signal transmission circuit 17. It is now being transmitted and sent out as a. Similarly, data signals transmitted through the power line 3 are also transmitted to the signal detection circuit 14 and the data signal conversion circuit 1.
6. The signal passes through the data signal sending circuit 18, is converted into a data signal for private line transmission, and is transmitted to the coaxial cable 2 side.

By exchanging data signals between the coaxial cable 2 and the power line 3 via the gateway 11 in this way, even in a system like the one shown in Figure 6, it is possible to remotely control loads such as lighting fixtures in the entire home from any room. This is the result.

[Problem that the invention seeks to solve]

A conventional information communication system is configured as described above. By the way, the speed of signals transmitted over coaxial cables and the speed of transmission over power lines are very different. For example, if a coaxial cable is 9600 bps, the speed of a power line is only about 100 bps. Therefore, if signals from the coaxial cable are uniformly transmitted to the power line, the communication load on the power line becomes excessive and the response becomes very poor. Information that is transmitted can be broadly divided into control information such as home control, and text information used in personal computers and the like. In home control, for example, when a control command is issued to turn on a light, it does not matter what kind of code the command is expressed in, as long as the light can be turned on. However, when transmitting text information, it is necessary to send each character and phrase as the same information, and the expression itself becomes a problem.

Therefore, when relaying data from a coaxial cable to a power line, it is necessary to identify whether the data is control information or text information, and if it is control information, the data must be abbreviated to the necessary and sufficient range. It is reasonable to relay the information, and if it is text information, to transmit it as is.

This invention was made to solve the above-mentioned problems, and its purpose is to reduce the communication load on power lines.

[Means for solving problems]

The information transmission system according to the present invention includes a gateway that converts signals between a dedicated transmission path and a power line, a conversion relay circuit that converts the expression method of control information, compresses or expands it, and relays it, and data such as text information. It is equipped with a simple relay circuit that simply relays the information using only a speed conversion relay, etc., and a switching circuit that detects the type of information and selects one of these relay circuits.

[Effect]

The conversion relay circuit of the gateway in this invention shortens information such as home control on the dedicated transmission line and relays it to the power line, thereby reducing the communication load on the power line. In addition, the simple relay circuit relays text information from a personal computer, etc. in the same representation format, eliminating errors in information transmission. Further, the switching means determines the type of information and selects an appropriate relay circuit from both relay circuits.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an example of the configuration of a gateway used in the present invention, and in the figure,
2 is a coaxial cable as a dedicated line, 3 is a power line, 19 is a simple relay circuit, 20 is a conversion relay circuit,
21 and 22 are switch circuits, and 23 is a switching control circuit. The switch circuits 21 and 22 and the switching control circuit 23 constitute a switching circuit 24.

In the gateway 11 configured as described above, the coaxial cable 2 is transmitted and the switch circuit 2 is connected.
The received frame input to 1 is sent to switching control circuit 2.
Sent to 3. The switching control circuit 23 selects either the simple relay circuit 19 or the conversion relay circuit 20 from the code included in the received frame. For example, when the simple relay circuit 19 is selected, the received data is transferred to the simple relay circuit 19 via the switch circuit 21.
Here, the data format of the coaxial cable 21 is converted into the data format of the power line 3, and then transmitted to the power line 3 via the switch circuit 22. The procedure for relaying from the coaxial cable 2 to the power line 3 has been described above.

When relaying from the power line 3 to the coaxial cable 2, the switching control circuit 23 is connected via the switch circuit 22.
data is sent to. Next, the simple relay circuit 19 or the conversion relay circuit 20 is selected, and the switch circuit 2
1, data is relayed to a coaxial cable 2.

In the above, the simple relay circuit 19 is a circuit that transparently relays data in a transmission frame,
The conversion relay circuit 20 is a circuit that compresses or expands data in a transmission frame and then relays the compressed or expanded data.

Next, a home control system using the gateway 11 according to the present invention will be explained. In Figure 1, 2 is a coaxial cable, 3 is a power line, 11 is a gateway, 25 is a central controller, 26 is an outlet adapter, which controls the ON/OFF of loads 6 such as lighting and home appliances, and 27 is a telephone system main. The device 28 is a telephone.

In the figure, the case where the outlet adapter 26 is controlled from the central controller 25 is considered. Figure 3 shows the parts necessary to explain the procedure. When the operation switch of the centralized controller 25 is pressed, a control command is issued from the centralized controller 25 to the gateway 11. This control command is transmitted through coaxial cable 2 to gateway 1.
1, the gateway 11 decodes this data and learns which outlet adapter 26 the central controller 25 wants to control. Next, the gateway 11 transmits extremely short data necessary for control to the outlet adapter 26. Upon receiving this, the outlet adapter 26 controls the home appliance 6 and then returns a monitor response indicating the ON/OFF state of the home appliance. Upon receiving this, the gateway 11 sends the necessary data (a code indicating that it is a monitor, a code indicating that it is information about an outlet adapter, the number of an outlet adapter, etc.) so that it conforms to the format decoded by the central controller 25. is added and the data is relayed to coaxial cable 2. This data is received by the central controller 25 and the display is updated.

FIG. 4 illustrates the communication procedure described above.

FIG. 5 shows a sequence when the gateway 11 directly issues a control command, and the monitor response is also relayed to the centralized controller 25.

FIG. 6 shows a communication frame transmitted on the coaxial cable 2, where 29 is a transmitting station address, 30 is a receiving station address, 31 is a control word, and 3
2 is the number of data bytes, 33 is data, and 34 is a frame check sequence.

FIG. 7 shows the format of a communication frame on the power line 3, where 35 is a preamble, 36 is a transmitting station address, 37 is a receiving station address, 38 is a control word, 39 is the number of data bytes, 40 is data, and 41 is a This is a frame check sequence.

Frame format on coaxial cable 2 and power line 3
There are no major differences in the frame formats above.
However, while a frame on the coaxial cable 2 consists of 5 bytes or more, the data length on the power line 3 is 1 byte or less.

The reason for this is that since many terminals are connected to the coaxial cable 2 and the controls are diverse, scalable data expression is used, but instead the data length is long. Furthermore, on the power line 3, the connected devices are simple ON/OFF loads, the transmission speed is low, and short data is convenient.

Therefore, when relaying home control information from the coaxial cable 2 to the power line 3, the gateway 11 compresses the data, and conversely, when relaying data from the power line 3 to the coaxial cable 2, it adds necessary data. .

Next, the procedure for communicating text information between personal computers and the like will be explained.

In FIG. 8, 42 is a terminal such as a personal computer connected to the coaxial cable 2, and 43 is a terminal such as a personal computer connected to the power line 3.

Unlike home control, when transmitting text information between computers, the purpose is to send and receive the same data in the same representation format between the computers. Therefore, the gateway 11 is required to relay the data part as it is, rather than decoding and converting the details of the data.

Figures 9 and 10 both show the coaxial cable 2.
This is the frame above. FIG. 9 shows a frame transmitted from the terminal 42, and FIG. 10 shows a frame transmitted toward the terminal 42.

In FIG. 9, 321 is a header, which indicates that the data is text data and should be simply relayed. 332 is a destination network address and indicates relaying to a power line. 333 is the address of the terminal on the power line. 334 is data to be sent to the terminal 43.

In FIG. 10, 335 is a source network address indicating that it is sent from a terminal on power line 3, and 336 is the address of the terminal on power line 3.

Data is exchanged between personal computers using the format shown in FIGS. 9 and 10 above.

Switching between converted relay and simple relay as described above is identified by the header 321. Data instructing the selection of conversion relay or simple relay is placed in this header and sent to the gateway 11, and the gateway 11 uses this to select conversion relay or simple relay.
Perform simple relay.

In FIGS. 11 and 12, communication protocols are described using layer representations. In the figure, 1
4 is a physical layer, 45 is a data link layer, 46 is a network layer, 47 is a transport layer, 48 is a session layer, 49 is a presentation layer, and 50 is an application layer.

FIG. 11 shows connections between layers of each device during simple relay. The data of the terminal device 42 is connected to the gateway 11 through a network layer 46.

FIG. 12 shows connections between layers of each device during conversion relay. The data of the centralized controller 25 is once decoded by the gateway 11, further generated, and received by the outlet controller 5.

In the above embodiment, the relay between the power line and the coaxial cable was described, but any network may be used. Furthermore, the protocol layer to be connected can be arbitrarily selected.

〔Effect of the invention〕

As described above, according to the present invention, a conversion relay circuit converts the representation method of gateway control information inserted between a dedicated transmission line that transmits digital signals at high speed and a power line that transmits digital signals at low speed, and relays the information. A simple relay circuit that simply relays data such as text information as it is, and a switching circuit that selects both relay circuits are provided, so the communication load on the power line can be minimized, and Text transmission between personal computers has also become possible.

[Brief explanation of the drawing]

FIG. 1 is a system block diagram of a load control device using an information transmission system according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a gateway used in FIG. 1, and FIGS. Figure 6 is a communication procedure diagram showing each communication procedure by the device in Figure 1. Figure 6 is a frame configuration diagram on a coaxial cable using the equipment in Figure 1. Figure 7 is a frame configuration diagram on a power line as well.
Figure 9 is a system diagram showing another embodiment according to the present invention, Figure 9 is a configuration diagram of frames transmitted from the terminal, Figure 10 is a configuration diagram of frames transmitted to the terminal, and Figure 11 is a protocol layer during simple relay. FIG. 12 is a configuration diagram of a protocol layer during conversion and relay, FIG. 13 is a system diagram of a load control device using a conventional information transmission system, and FIG. 14 is a configuration diagram of its gateway. Codes in the diagram: 2 is a coaxial cable, 3 is a power line, 1
1 is a gateway, 19 is a simple relay circuit, 20 is a conversion relay circuit, 21 and 22 are switch circuits, 23
2 is a switching control circuit, and 24 is a switching circuit. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A gateway is inserted between a system that transmits high-speed digital signals using a dedicated transmission line such as a coaxial cable and a system that transmits low-speed digital signals using power line transport, and that relays signals between the two systems. However, in an information transmission system that sends and receives signals between these two systems, when data is relayed between the dedicated transmission line and the power line to the gateway, when the relay signal is text information used by a personal computer, etc. A simple relay circuit that transparently relays the data in the transmission frame, a conversion relay circuit that compresses or expands the data in the transmission frame and then relays it when the signal is control information such as home control, and a conversion relay circuit that relays the data in the transmission frame when the signal is control information such as home control. An information transmission system characterized by comprising a switching circuit that detects and switches between both relay circuits. 2. The information transmission system according to claim 1, wherein the switching circuit detects the type of signal from the received transmission frame and switches between the two relay circuits.